by Nicolás Bernal (ICTP – SAIFR, São Paulo, Brazil)

Thursday, 18 June 2015 from to (Europe/Madrid)
at IFIC ( Seminar Room 1.1.1 )

ABSTRACT

We propose and study a scalar extension of the Standard Model which
respects a ℤ3 symmetry remnant of the spontaneous breaking of a global
U(1) symmetry. Consequently, this model has a natural dark matter
candidate and a Goldstone boson in the physical spectrum. In addition,
the Higgs boson properties are changed with respect to the Standard
Model due to the mixing with a new particle. We explore regions in
the parameter space taking into account bounds from the measured Higgs
properties, dark matter direct detection as well as measurements of
the effective number of neutrino species before recombination. The dark
matter relic density is determined by three classes of processes:
the usual self-annihilation, semi-annihilation and purely dark matter
3→2 processes. The latter has been subject of recent interest leading
to the so-called `Strongly Interacting Massive Particle' (SIMP) scenario.
We show under which conditions our model can lead to a concrete
realization of such scenario and study the possibility that the dark
matter self-interactions could address the small scale structure problems.
In particular, we find that in order for the SIMP scenario to work,
the dark matter mass must be in the range 7−115 MeV, with the global
symmetry energy breaking scale in the TeV range.
http://indico.ific.uv.es/indico/conferenceDisplay.py?confId=2483